In certain industries (e.g., construction, service maintenance, package delivery), many vehicles are continuously dispatched from one location to another. A central dispatcher uses a scheduling algorithm to schedule the transit of each vehicle from one location to another in an attempt to maximize vehicle usage and minimize travel times of the vehicles. Travel times and/or travel distances between locations are estimated and stored in the cells of an in-memory travel matrix as part of a database system. The travel matrix can become very large as the number of locations, travel conditions, and vehicle conditions grows. As a result, computer memory in the database system can become very large (e.g., too large to implement or manage). Furthermore, time delays associated with accessing the travel matrix in the database system can become unacceptable, adversely affecting system dispatching performance.